There's no doubt that the reusable water bottle market is an overcrowded one … slap a “BPA-free” label on it, market it as a “green” alternative to single-use plastic water bottles and you’re pretty much good to go. Bonus points are awarded if you go the Bobble route and add a built-in filter.

Enter Dan Black and Martin Blum of London-based product design firm, black + blum. This endlessly clever Anglo-Swiss duo have long excelled at injecting good looks and innovation into functional yet otherwise humdrum housewares like staplers, desk fans, toilet paper holders, and potato mashers. Hell, they managed to make the dish rack look sexy. One of the black + blum’s newer designs, a portable grill/herb garden combo called the Hot-Pot BBQ (previously featured on this here blog) has managed, most deservedly, to snag a whole bunch of design awards including the Excellence in Product Design and Blogger’s Choice awards at last year’s New York International Gift Fair.

Yesterday, I spent a couple of hours navigating the winter installment of NYIGF 2012 and had the pleasure of checking out black + blum’s newest creation which is, yep, a reusable water bottle. After getting a tutorial of the bottle, called Eau Good, by Dan Black himself, I have this to say: As a sustainable design blogger, more than a couple reusable water bottles have been brought to my attention but it takes a lot for one to grab it. Eau Good managed to do that and then some.

Complementing black + blum’s bento-inspired lunchbox range, Eau Good features a unique, vintage glass bottle shape (it’s made from BPA-free PET), a natural cork stopper, and a big ole cylindrical chunk of binchotan activated charcoal that sits snugly at the bottom of the bottle itself — no twist-off carbon filter top here — where it removes tap water impurities such as chlorine, balances the water’s PH level, and adds essential minerals to your eau.

The stick of activated charcoal, a substance of that's been used in Japan as a natural water purifier since the 17th century, locks into place when the bottle is squeezed. The ingenious “squeeze lock” feature also release the carbon filter when it needs to be changed. With a lifespan of about six months, post-Eau Good the filter can be reused around the house for several more months. I'd recommend dropping it at the bottom of a kitchen trash can or placing it near a liter box or in a mothball-y drawer to help absorb unwanted odors. Refills are available so you do don’t have to buy a new bottle every six months.

Good but not necessarily game-changing stuff — the folks at the Home show in London seem to agree as Eau Good recently picked up the Best New Product prize at that event — although the design may freak out those who may balk at foreign objects, no matter how beneficial, sitting in their water. Also, I'm still a bit hazy on how effective a piece of activated carbon sitting in water is versus a traditional activated carbon filter that water passes through. Eau Good will soon be available at retailers and through black + blum's online store; they'll sell for $20. And stay tuned for more highlights from NYIGF in the coming days ...